Journal cover Journal topic
Atmospheric Chemistry and Physics An interactive open-access journal of the European Geosciences Union
Atmos. Chem. Phys., 16, 7531-7543, 2016
https://doi.org/10.5194/acp-16-7531-2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.
Research article
20 Jun 2016
Results from the validation campaign of the ozone radiometer GROMOS-C at the NDACC station of Réunion island
Susana Fernandez1, Rolf Rüfenacht1,a, Niklaus Kämpfer1, Thierry Portafaix2, Françoise Posny2, and Guillaume Payen3 1Institute of Applied Physics, University of Bern, Bern, Switzerland
2LACy, Université de la Réunion, Saint Denis, France
3OSU-Réunion, Université de la Réunion, Saint Denis, France
anow at: Leibniz-Institute of Atmospheric Physics, Kühlungsborn, Germany
Abstract. Ozone performs a key role in the middle atmosphere and its monitoring is thus necessary.

At the Institute of Applied Physics of the University of Bern, Switzerland, we built a new ground-based microwave radiometer, GROMOS-C (GRound based Ozone MOnitoring System for Campaigns). It has a compact design and can be operated remotely with very little maintenance requirements, being therefore suitable for remote deployments. It has been conceived to measure the vertical distribution of ozone in the middle atmosphere, by observing pressure-broadened emission spectra at a frequency of 110.836 GHz. In addition, meridional and zonal wind profiles can be retrieved, based on the Doppler shift of the ozone line measured in the four directions of observation (north, east, south and west).

In June 2014 the radiometer was installed at the Maïdo observatory, on Réunion island (21.2° S, 55.5° E). High-resolution ozone spectra were recorded continuously over 7 months. Vertical profiles of ozone have been retrieved through an optimal estimation inversion process, using the Atmospheric Radiative Transfer Simulator ARTS2 as the forward model. The validation is performed against ozone profiles from the Microwave Limb Sounder (MLS) on the Aura satellite, the ozone lidar located at the observatory and with ozone profiles from weekly radiosondes. Zonal and meridional winds retrieved from GROMOS-C data are validated against another wind radiometer located in situ, WIRA. In addition, we compare both ozone and winds with ECMWF (European Centre for Medium-Range Weather Forecasts) model data. Results show that GROMOS-C provides reliable ozone profiles between 30 and 0.02 hPa. The comparison with lidar profiles shows a very good agreement at all levels. The accordance with the MLS data set is within 5 % for pressure levels between 25 and 0.2 hPa. GROMOS-C's wind profiles are in good agreement with the observations by WIRA and with the model data, differences are below 5 m s−1 for both.


Citation: Fernandez, S., Rüfenacht, R., Kämpfer, N., Portafaix, T., Posny, F., and Payen, G.: Results from the validation campaign of the ozone radiometer GROMOS-C at the NDACC station of Réunion island, Atmos. Chem. Phys., 16, 7531-7543, https://doi.org/10.5194/acp-16-7531-2016, 2016.
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Short summary
We present a new ground based microwave radiometer for campaigns, GROMOS-C. It measures the vertical distribution of ozone in the middle atmosphere by observing spectra at 110.836 GHz. The paper presents a validation campaign that took place on La Réunion Island. The ozone retrieved profiles are validated against ozone profiles from the Microwave Limb Sounder, the ozone lidar located in the observatory, ozone profiles from weekly radiosondes and with ECMWF model data.
We present a new ground based microwave radiometer for campaigns, GROMOS-C. It measures the...
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